Dishonored 2 demo is out now and is ~20Gb Fret not, it included full 3 missions and both playable characters. If you decide to upgrade to full game later, all progress will be carried over and not lost.

Void engine is pretty damn good looking and snappy. Rumored to be built off id Tech 5.

Also can be played in VR via VorpX (I noticed there is an option to disable head bobbing - useful for VR)